Roll film camera with spring motor



P 1941. L. LEI-r2 irrAL ROLL FILM CAMERA WITH SPRING MOTOR 2Sheets-Sheet 1' Filed April 19, 1939 Sept. 16, 1941. LE|TZ ETAL2,256,207

ROLL FILM CAMERA WITH SPRING-MOTOR Filed April 19, 1939 2 Sheets-Sheet 2IV w m mulmiu gg Patented Sept. 16, 1941 v UNITED STATES PATENT OFFICEnommsscmnswmrsramo uo'ron Ludwig Leltl and Heinrich Broschke, Wetaiar,

Germany, assignors, by meme alaig'nmenta'to FrankDum ur, Lausanne,Switleriand May 12, 1938 This invention relates to roll film cameraswith focal plane shutters which include as a part of the cameramechanism a self-starting spring motor for actuating the film advancingmechanism and for actuating the shutter rewinding mechanism for eithersingle exposures or series of exposures. The spring motor may bebuilt-in or it may be detachable as an accessory to the camera. Camerasincluding spring motors for the purposes mentioned are known but theysuffer from the disadvantage that the running-off speed of the springmotor cannot be synchronized with the shutter speeds; or that'for thispurpose a special arrangement is required which so limits the relationor ratio of the motor speed to the shutter speed that a series ofpictures can be taken only with very short exposures. If longerexposures are demanded or desirable, then the motor, because of its evenregular speed, starts to advance the film before the exposure isfinished.

. To overcome this trouble it has been proposed to regulate or influencethe operation of the motor speed governor in such a manner that it wouldalso control the number of revolutions of the spring motor. This howevercan be done only within very narrow limits. 7

The object of this invention is to provide a generally improved springmotor mechanism to be used with a roll film camera having a focal planecurtain shutter, said mechanism embodying clude that the force of thecurtain movement shall also ercome the tension of the motor springs.That is to say, the movement of the follow-up curtain is utilized onlyfor the release of the spring motor and in effecting this release thecurtain is notemployed to overcome the tension orresistance of thesprings in the motor.

The invention is embodied in a'spring motor and camera mechanism inwhich the follow-up curtain of the shutter at the end of its shutterclosing movement actuates a mechanical relay which then inturn by meansof a spring releases the motor. The spring motor itself after havingbeen released causes the relay to be brought back into its originalready position so that the operating cycle may be continued for eachexposure. This construction insures that the spring motor be not starteduntil after an exposure has been finished.

Some attempts have been made to have the follow-up curtain release thespring motor. Such 2 Claims. (CI. 95-31) attempts included aconstruction in which the curtain by striking against a stop pawlreleased a gear on the film winding up roller and thus released thespring motor. Such an arrangement was not practical and could not beused because the entire force of the motor spring acts upon such gearand stop pawl and the curtain spring, which at the end of the curtainclosing movement is almost entirelywithout tension, was not strongenough to overcome the force of the motor spring acting upon the stoppawl.

The invention is embodied in a camera and motor mechanism arranged andconstructed as hereinafter set forth and as illustrated in the.

accompanying drawings in which Fig. l is a sectional view of the cameraand Figs. 3 and 4 show some mechanisms in Fig.1

indifferent positions. Parts are sectioned and broken away.

Zt"igs. 5 and 6 illustrate a modification.

Referring first to Figs. 1 to 4 the camera i is of a type andconstruction well known in the art. For the purposes of this inventionit will be suillcient to identify the camera mechanism by the objectiveII, the film spools ii and i2 and the depressible shutter release llwhich passes down-- ward-through the film transport roller 2. The camerais provided with a focal plane shutter of the .type shown in U. 8.Patent 2,122,671, July'5, 1938. The shutter consists of two shuttercurtains. The one edge of the leading curtain II is secured to and woundup upon a curtain spring roller I. The other edge of said curtain is asusual connected by ribbons to winding up drums 8 on the curtain rollershaft 25. The leading curtain is broken away as shown and its connectionto the drums I are not shown, being well known. The follow-up or secondcurtain H is at its one edge connected to and .it is wound up-uponthecurtain roller 3 on the said-shaft 2|. The other edge of the secondcurtain H is connected by ribbons I to another winding up spring rollerwhich lies directly behind the roller 4 and therefore is not visible inthe drawing. said ribbons 6 passing around an idler roller II on the'shaft of the winding up roller 4. In making an exposure a gear 2| whichmeshes with a pinion 24. The

' of this type of focal plane shutter is well latter in turn drives agear 11 on thefilm transport roller 2. The pinion 24 is fast on a shaft23 which is driven by the spring motor. -When the latter is released theshaft 23 and pinion 24 are rotated so that on the one hand the curtainroller and drums may be rotated to wind up the shutter curtains and thesprings, not shown, in the curtain rollers. and on the other hand thefilm transport roller may be rotated to wind up and advance the film.The construction and operation known and understood in the art.

The spring motor 1 may be buiit-inor it may be detachably connected tothe camera. The springs 8 and 9 are shown as being coaxial with the filmspools 1| and 12. The two springs are operatively connected by a numberof gears marked IO, N, l2, l3, l4 and I5. The gear l2, upon which bothsprings act at the same time, is fast on the motor drive shaft IS. Thelatter also carries a gear H which by means of gears 18, i9 and 29 isoperatively connected 'to a governor disk 2|. To the other side the gearI I1 meshes with a gear 22 fast on the aforesaidshaft 23. The gear I1 isprovided with a blank 33 the free end 34 of which rests upon the uprightarm 35 which is part of a lever 31 pivoted at 36. The right hand end ofthis lever 31 carries a pin 42. The left hand end of' the lever 31 isformed with-a "hook 4| adapted to engage in the said recess 3| in thedisk 29, see Fig. 4. The lever 33 has also an upstandin hook 38 whichengages an annular groove 18 in the-said gear 28 on the curtain rollershaft 25., A spring 39 urges the lever 33 downward.

The pin 42 in the lever 31 is adapted to be engaged by a hook 43 on abell crank 46 which clockwise about its pivot 36 by a downward movementof the long thin lever 33 under pres-- is pivoted at. 44. A spring keepsthe bell.

crank in engagement with the pin 42, Fig. 1, and also keeps the arm 41of the bell crank up against the lower end of the depressible shutterrelease 48. Another two armed lever 49 is pivoted at 50. The right handend of this lever is upwardly inclined as at 53 and forms a hook 52adapted to engage the tooth 28 on the ar 21, Fig. 3. The inclined camsurface 53 is adapted to be engaged by'the nose 30 on the disk 29.

The left hand arm 54 of the lever 49 is pressed downward by a spring 55against a stop 6|. The spring acts against a foot 56 which is part -ofthe lever arm 54. Secured to the arm 54 is a leaf spring 58 whichextends upwards from' the arm at about a right angle. The upper end ofthe leaf spring 58 carries a hook 59 which is adapted to move in a cutout 89 in the camera wall as shown. The hook 59 is adapted to be knockedout of. its rest position on the edge .of the opening 69, Fig. 3, by apin'63 'on the second curtain.

At this time the positions of the several parts of the mechanisms shouldbe noted as they are shown in the drawings. Fig. 1' shows the parts inthe positions which they assume immediately after the motor has beenreleased and the shutter is being rewound and the film advanced. It willbe noted that the disk 29 has been rotated by,. the motor sufilcientlyto move the hook 4| outof the disk recess 3| hence the lever '31 haslever 33 with'its upstanding hook 38 whereby to couple the gear member26 with the curtain roller shaft 25. The curtain roller has now startedto rewind the shutter, the edges of the curtains being closed as at 15.On the other hand, the arm 54 of the lever 49 has been depressed by thespring 55 so that the hook 52 of said lever lies above the tooth 28 onthe gear l1. The latter therefore is rotating, the motor being released.

Fig. 3 shows the positions at or near the end of an exposure, theexposure opening being betweenthe curtains 13 and 14 as shown. Here itwill be seen that the motor is not released because rotation of the gearI1 is prevented by the engagement of the hook 52 with the tooth 28. Fig.4 shows that the shutter release has just been operated to tip the bellcrank 46 to permit the lever 33 to be moved down by the spring 39whereby to uncouple the gear member 26 from the curtain roller which isnow free to rotate so that the shutter may be opened.

The operation is as follows: Let it be supposed that the motor springs 8and 9 have been tensioned by rotating the handle 62 at the bottom of,the motor casing and the camera is ready to be operated. At this timethe shutter is closed because the shutter release has not beendepressed, hence the bell crank 46 is locked, the long thin lever 33 isin its upper position against the wall 40 and the gear member 26 iscoupled to the curtain roller shaft 25, which therefore cannot rotate.This situation is pictured to the right in Fig. 1. At the same time themotor is prevented from rotation because the hook 52 lies in front ofthe tooth 28 as shown in Fig. 3.

When an exposure is to be made the photographer presses down upon theshutter release 48 and thereby tips the bell crank 46 clockwise,

sure by the spring 39 and the hook 4| of said lever 31 snaps up into therecess 3| in the disk 29. As soon as the lever 33 moves down; itsupstanding hook 38 pulls down the coupling gear member 26 anduncouplesthe same from thecurtain roller. The latter is now free to rotate andthe shutter is opened to make the exposure.

At the end of the exposure the pin 63 on th second curtain 14 runsagainst the hook 59 on the leaf spring 58 and knocks it off the edge ofthe opening 68. As soon as this happens the spring 55 depresses the arm54 of the lever 49, see Fig.

1, and lifts the hook 52 above the tooth 28, the

' lever 31 lifts the lever 33 against the pressure of the spring 39-tocause the upstanding hook 38 to lift the gear member 26 and couple thesame to the curtain roller shaft 25, the shutter, starts to rewind andthe film transport roller 2 starts to rotate to advance the film. Thepin 42 on the bell crank snaps in behind the same and is locked in thatposition by the spring 45. Therelease 48 is returned to its upper normalposibeen tipped anticlockwise to lift the long thin tion.

After the disk 29 has been rotated still further by the motor, theradially disposed nose 30 on the disk engages the inclined cam surface53 of the lever 49 and causes said lever to be tipped clockwise aboutits pivot 58 to bring the hook 52 down upon the gear H in the path ofthe tooth 28. When the latter reaches the book 52 the motor stops. Thetipping of the lever 49 causes the leaf spring to be raised and its hook59 is again hooked in over the edge of the opening 60 so that the lever49 remains in downward tipped motor locking position. x

A complete rotation of the drive shaft l6 and the gear I! is sufiicientto accomplish the advancement of the film one picture length and thecomplete rewinding of the shutter. The blank portion 21 on the gear I!serves to permit the lever 31 to cause the lifting of the gear member 26to complete the coupling thereof with the curtain roller shaft beforethe gear 22 begins to be rotated by said gear l1. Were this blankportion 21 not provided, it might happen that the coupling 16 would notbe completed in time, so that, although the film would be advanced byoperation of the gear 22, shaft 23 and pinion 24, the shutter might notbe rewound I or only partly rewound.

Figs. and 6 illustrate a modification in which the pin 63 is removedfrom the second curtain and the hook 59 on the leaf spring 58 isknockedoff the edge of the opening 68 by a tooth 65 which is carried bya gear 66 as seen in Fig. 6. The gear 66 is driven from the roller 85 onthe shaft of the winding up roller 4 by means of gears 64 and 86. Whenthe shutter is opened the ribbons 6 of the second curtain are drawnaround and rotate the roller 85 before being wound up upon the secondspring curtain roller which is not shown in the drawing. The number ofteeth and proportions of the gears 64, 68 and 86 are such that at theend of the shutter opening movement the tooth 65 strikes the hook 59 andknocks it into the opening 60 with the results as above described. Thearrangement in Figs. 5 and 6 possesses the advantage that the secondcurtain itself is not burdened with any motor releasing member such asthe pin 63. On the other hand there is the advantage that the gears 64,66 and 86 act in the nature of an escapement which results in an evenmovement of the second curtain.

The two armed lever 31 maybe considered as a mechanical relay forreleasing the shutter and whereby particular advantages are obtained notonly in a motor driven camera but for cameras generally. Shutterreleases as usually constructed and operated are one of the main causesfor the tearing or irregular movements of the film because of themechanical resistances to be overcome by the release. Such adisadvantage or objectionable feature is completely eliminated by usinga relay as herein disclosed because the operation of the shutter Irelease 48 only serves to release the relay whereas the real shutterrelease is accomplished by the spring 8!. Again, in a shutter releaseaccording to the I invention the resistance against the operation of therelease 48 is always the same and the parts may be constructedaccordingly. Such resistance is much less than that which is to beovercome in ordinary releasing mechanisms. Another advantage is that themechanical relay may be accurately calculated and constructed withfreedom from vibration and exact proportions as circumstances mayrequire. The same or similar advantages are obtained by using a relaysuch as the lever 49 for releasing the motor.

It will be noted that the only resistance against operation of therelease 48 is caused by the fiat spring and all other work to beperformed in operating the shutter release is caused by the spring 40and the motor which drives the disk 29. Likewise the resistance againstthe pin 63 on the second curtain or against the tooth to release thesecond relay 49 is caused only by the leaf spring 58 which keeps thehook 59 in position on the edge of the opening 60. Thus more or lessviolence or power otherwise required to release the shutter and themotor are eliminated. A more smooth and evenly balanced operation isobtained.

We claim:

1. In a motor driven camera, a focal plane shutter including a leadingand a following shutter curtain, rewinding means therefor, a selfstarting spring motor for driving said rewinding means, a lever relaydevice engaging said motor for holding the same normally inactive, ahook connected to said relay and normally held thereby in the path ofmovement of said following shutter curtain to latch the relay inholding' position, a shutter release for opening the shutter to make anexposure, means carried on said following shutter curtain engaging saidhook at the end of its movement to release the same from its saidnormally held position and a spring urging said relay away from theholding position and operable upon the release of said hook foractuating said relay to release the motor to drive said rewinding means.

2. In a motor driven camera, a focal plane shutter including a leadingand a following shutter curtain, opening means and rewinding means forsaid shutter, a self starting spring motor for driving said rewindingmeans, a first relay for normally operatively connecting the shutter andits rewinding means and to hold the shutter in closed position, ashutter release for actuating said first relay to disengage the shutterfrom its rewinding means and open the shutter, a second relay having anormal position for engaging said motor to hold the same inactive, meanson said following shutter curtain to actuate said second relay torelease the motor to operate said first relay to operatively connect theshutter with its rewinding means and to drive the latter to rewind theshutter after an.

exposure and means on the motor for moving said second relay back to itssaid normal position after the shutter has been rewound.

LUDWIG LEITZ. HEINRICH

